Kinda surprised no one is talking about Siemen's new electric motor

Well, a light electric motor is certainly important, but you also need light batteries that won't burn in turbulence, hundreds of miles of range, and a recharge cycle shorter than a flight in order to "revolutionize" GA.

It's one piece. By itself, it's going to be rather unimportant. It needs other stuff to work.
 
Still have the weight problem of the batteries,also takes to long to recharge ,not much good on long cross countries. They are the future.
 
My understanding is that it's a hybrid system. It has an on-board gas or diesel motor to spin a generator to supplement the battery.
 
frfly172 said:
Still have the weight problem of the batteries,also takes to long to recharge ,not much good on long cross countries. They are the future.
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Well, I still think it is a fairly exciting development.
Why does everyone always have to find some kind of fault with everything? Developing technology is always going to have some obstacles to overcome.
 
I'm still trying to figure out how that'll work trailing an extension cord?:rofl:
 
It is reported that after taxiing to the runway for departure, the aircraft must return to its hangar for recharging.
 
I'll get excited when I can go rent one for $50/hr. But as gas isn't that much % of rental fee, thats a pipe dream. Maybe lower maintenance would shave off a bit more hourly, although they prolly won't pass the saving on to the renter, just pocket that $$.

For real though, I thought it was a promising development.
 
Shepherd said:
My understanding is that it's a hybrid system. It has an on-board gas or diesel motor to spin a generator to supplement the battery.
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Please explain to me: What is the engineering logic behind a hybrid powerplant in an aircraft (other than maybe a self-launch glider)? On surface vehicles it makes sense because of the energy recovery during deceleration, but I'm having a hard time getting my brain around where the advantage would be in aircraft.

Thanks.

Rich
 
RJM62 said:
Please explain to me: What is the engineering logic behind a hybrid powerplant in an aircraft (other than maybe a self-launch glider)? On surface vehicles it makes sense because of the energy recovery during deceleration, but I'm having a hard time getting my brain around where the advantage would be in aircraft.

Thanks.

Rich
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The hybrid uses stored energy for acceleration....and optimizes the cruise or operating performance with a smaller more efficient power generation engine.

Like you....I'm doubtful the hybrid is a solution that will find it's way into aircraft. For the most part aviation engines are very efficient at converting BTUs into workable power. Hybrids make lots of sense for autos because they tend to operate at such a low % of their capability.....something of the order of 20-30%HP.
 
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You can mount wind turbines on the wings and create the worlds first perpetual motion aircraft. I'm calling the patent office now.
 
JOhnH said:
Well, I still think it is a fairly exciting development.
Why does everyone always have to find some kind of fault with everything? Developing technology is always going to have some obstacles to overcome.
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Because a powerful motor with heavy batteries is not developing technology, it's undeveloped technology. And probably because an electric motor isn't exactly sexy new technology, electric motors have been around for over 100 years.

Now - if someone can come up with a hybrid system similar to a Prius which halves the fuel burn, then people will be getting excited.

Also 260kW is a lot of power, about 30% of whats needed to run an average house. A Tesla, the best electric car in the world, has about a 80kWh battery, about 1200 lbs. Until batteries catch up, the joke about the extension cord is not far from the truth.

The number don't add up yet.
 
Motor efficiency will need to make massive improvements to overcome the much lower energy storage density of batteries compared to IC fuels. The article posits a significant improvement in torque/KG of weight, when what they need to work on is torque/KW of energy applied. I would say they need at least a doubling, or better yet a tripling of the torque produced to approach IC engine range and thrust.

Couple this with paradigm shifts in battery energy improvements, and anything like a true motor/battery useful aircraft like an SR-22 is decades/forever away. So far the improvements have been on a percentage scale(8-30%) when they need to be on a multiples scale(200-300%) to make a diff.
 
Anthony said:
It is reported that after taxiing to the runway for departure, the aircraft must return to its hangar for recharging.
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You don't need to do that, the run-up areas have plugs ready and waiting.
 
RJM62 said:
Please explain to me: What is the engineering logic behind a hybrid powerplant in an aircraft (other than maybe a self-launch glider)? On surface vehicles it makes sense because of the energy recovery during deceleration, but I'm having a hard time getting my brain around where the advantage would be in aircraft.

Thanks.

Rich
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You have more flexibility in where to mount the prime mover and the propeller(s), plus you aren't constrained by prop speeds so you might be able to downsize the engine. I can see some plusses here. Again, there are a lot of things that need to be worked out.
 
Checkout_my_Six said:
The hybrid uses stored energy for acceleration....and optimizes the cruise or operating performance with a smaller more efficient power generation engine.

Like you....I'm doubtful the hybrid is a solution that will find it's way into aircraft. For the most part aviation engines are very efficient at converting BTUs into workable power.
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I'm neither a physicist nor a mechanical engineer, but I'm inclined to agree.

One exception might be self-launch gliders that are actually used as intended rather than as powered airplanes. In the intended use, the powerplant is only used during taxi, takeoff, and often landing; so the increased weight of the battery and generator might be offset by the ability to use a smaller engine and to carry less fuel. The battery power could be used for takeoff, and then the battery charged during the flight.

I'm only thinking hypothetically, mind you. I haven't actually done the math.

This thread reminds me of the Sunseeker Duo project. Really cool stuff.

Rich
 
What was explained to me by a motor engineer is this: The ultra efficient motor has an infinitely long radial armature, with an infinitely large magnet(s) at the end(s), induced by an infinitely small current to produce the torque. Oh, and it needs to be encased in a vacuum to reduce rotational drag. As with everything, the packaging of the motors is going the other way. I was reminded of this when I glanced at the motor package they have in the pic. Most motors have a long aspect ratio like a pool pump motor with stubby armature. This robs the radial torque multiplier of each gauss of flux line and is detrimental to the optimum motor design. The package in the pic appears to be rather stubby in axial length and rather fatter in radial dimension thus achieving a better package efficiency over other motors of similar torque, and reducing the amount of weight in the armature, which reduces the need for that big structure to carry it.

Now, I'm out in left field on this kind of stuff, but I'm thinking some kind of long, stretched out linear motor, operating in recip fashion with an angle drive gear box at one end. Then, we're dealing with the overhead of the gear box, and the associated framing of a long slender linear motor.

Sigh--- can't win I guess.
 
There is still room for improvement in the engine in the article.

There is plenty of room for improvement in battery technology, and a lot of really smart people are working on that.

The cost of avgas is going to go (significantly?)up over time.

Most planes GA airplanes don't fly every day. These would be prime candidates for
solar battery recharging while photovoltaic conversion efficiency is seeing dramatic improvements.

As for hybrids, tune the gas engine for cruise power. Use battery assist during climb and during descent the engine could recharge batteries. In fact, during cruise, it could probably run on battery alone for a while with a solar recharging system.

Of course I know that none of this can work today. But that doesn't mean nobody should be working on it, or that they should be derided or ridiculed for doing so. People made fun of Henry Ford too. They were wrong.
 
Wouldn't a motors power be a product of its ability to shed heat? I read no mention of it's efficiency, just power to weight. If its horribly inefficient, it does little good for it to be 50% lighter.
 
frfly172 said:
Still have the weight problem of the batteries,also takes to long to recharge ,not much good on long cross countries. They are the future.
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054732806799lg.jpg


just plug a couple of these end to end. Don't need no batteries.
 
Subsea said:
Wouldn't a motors power be a product of its ability to shed heat? I read no mention of it's efficiency, just power to weight. If its horribly inefficient, it does little good for it to be 50% lighter.
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I didn't see anything in the article to shed light on the overall efficiency, but I would assume that most of the power to weight improvements were due to engine efficiency and not just brute force. I'd like to know more about that though.
 
Subsea said:
Wouldn't a motors power be a product of its ability to shed heat? I read no mention of it's efficiency, just power to weight. If its horribly inefficient, it does little good for it to be 50% lighter.
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Yes, and no. Motors are usually rated on duty cycle, where the heat shedding is one component of the duty cycle. However, the head loading of a motor is no where as high as that of an engine where combustion takes place. Of course, there is no combustion in the motor, so the heating effects are from the current in the windings, and the residual heat of the mass of metals from that current flow resistance.

A starter motor in a car has a 10% or so duty cycle. Hi torque, but for short duration. Most motors are 100% duty cycle at a specific torque rating. In aviation we may see motors rated at 260KW for x seconds on take off, and some lower 220KW continuous, partly for heat loading, and partly for coil saturation(an electrical thing).
 
One nice thing about a hybrid with a such an engine is it can be made to run off diesel. While a turbine can boast the same, I bet the hybrid electric comes out considerably cheaper.
 
jimbilly said:
I'll get excited when I can go rent one for $50/hr. But as gas isn't that much % of rental fee, thats a pipe dream. Maybe lower maintenance would shave off a bit more hourly, although they prolly won't pass the saving on to the renter, just pocket that $$.

For real though, I thought it was a promising development.
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On a 172, at least in my case, fuel accounts for about 40% of the rental cost. Higher fuel flow airplanes tend to have that percentage increase.

The rest is eaten up by insurance, hangar, oil, unplanned mx/upgrades, 100 hr inspections, engine reserve, and general business operating expenses.

It's pretty amazing to watch how much money flows into a rental bank account....and then watch how much of that rapidly flows right back out :)
 
Correct me if I'm wrong here, but I thought I read something a while ago about how internal combustion engines only convert about 1/3rd of the energy in their fuel to mechanical energy. Meanwhile an efficient electric motor can convert 90% or more of its input energy into mechanical energy.

So battery energy density doesn't quite need to reach that of current fuels, just needs to reach the point where a given volume (? might not be the right word) of input energy medium, be it gas or battery, gives you equivalent energy output from the engine.

Again, correct me if I'm wrong, I'm a computer guy, not an electrical/mechanical engineer.
 
It would be interesting to see the comparison of the efficiency of gas vs electric /power to weight. Gas holds about 33kwh/gal of energy....and if internal combustion is only 30% efficient (disregard the prop since we have to swing it in any scenario), then that make gas roughly 10kw/6 lbs/gal realized. I have no idea what batteries weigh vs output.

A cool thing about a battery bank is that it could be slid on rails to accommodate cg requirements.
 
I think one thing not being considered as an advantage would be the fact that an electric motor would not lose available power at higher altitudes so equivalent HP to gas pistons may not need to be a 1:1.

Electric motors are much more reliable than pistons and wouldn't require massive air inlets and would allow for much more efficient cowlings.

I recognize the battery is a major issue but coupled with the weight savings from getting rid of a large piston engine and liquid fuel would off-set some of the weight. If they pursued a gas-hybrid (like Chevy Volt or most diesel electric locomotives) I would think weight/range benchmarks could be made in time.
 
Fredbob711 said:
Correct me if I'm wrong here, but I thought I read something a while ago about how internal combustion engines only convert about 1/3rd of the energy in their fuel to mechanical energy. Meanwhile an efficient electric motor can convert 90% or more of its input energy into mechanical energy.

So battery energy density doesn't quite need to reach that of current fuels, just needs to reach the point where a given volume (? might not be the right word) of input energy medium, be it gas or battery, gives you equivalent energy output from the engine.

Again, correct me if I'm wrong, I'm a computer guy, not an electrical/mechanical engineer.
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Except that petroleum fuels exceed a battery's energy density by orders of magnitude.
 
Sac Arrow said:
Except that petroleum fuels exceed a battery's energy density by orders of magnitude.
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and you know what?.....the batteries are the heaviest part. Guess where those will go? ...at the C.G..:yes:

Yup, right under your seat.....ain't that gonna be the bomb sitting on all those LiPo batteries? :rofl:
 
Our prius V ( I stress this model) which is a station wagon, is truly amazing. Comfortable, plenty of pep, 40-41 mpg, nicely appointed, plenty of room,etc. I'm sure some experimental aircraft manufacturer will come up with something like this that will run on mo gas with ethanol, or straight Mogas. I can remember when this prius type engine was not even thought of. Plus it's very trouble free.
 
The Prius uses an internal combustion, four(Otto) cycle engine. It uses a modified Atkinson cycle valve geometry to improve combustion efficiency. All of the Toyota products are trouble free because they are very well built. I'm hoping the aviation community will take advantage of the improvements in auto engine designs. At least bring along a decent small diesel at lighter weight. This would be much better than a motor and batt combo.
 
Sac Arrow said:
You have more flexibility in where to mount the prime mover and the propeller(s), plus you aren't constrained by prop speeds so you might be able to downsize the engine. I can see some plusses here. Again, there are a lot of things that need to be worked out.
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you're spot-on, and that concept is already proven to work great. In boats. The system also has the advantage of taking the place of a little of the hundreds of tons of ballast that they use.
 
Jimmy cooper said:
Our prius V ( I stress this model) which is a station wagon, is truly amazing. Comfortable, plenty of pep, 40-41 mpg, nicely appointed, plenty of room,etc.
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yeah, they've done a great job of coming up with something very complicated that delivers the same room and only slightly worse mileage than an old VW diesel.
 
Fredbob711 said:
Correct me if I'm wrong here, but I thought I read something a while ago about how internal combustion engines only convert about 1/3rd of the energy in their fuel to mechanical energy. Meanwhile an efficient electric motor can convert 90% or more of its input energy into mechanical energy.

So battery energy density doesn't quite need to reach that of current fuels, just needs to reach the point where a given volume (? might not be the right word) of input energy medium, be it gas or battery, gives you equivalent energy output from the engine.

Again, correct me if I'm wrong, I'm a computer guy, not an electrical/mechanical engineer.
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that's all true. Now, where did the electricity come from? Does it just flow into the batteries from a magic plug in your garage ?
 
Jimmy cooper said:
Our prius V ( I stress this model) which is a station wagon, is truly amazing. Comfortable, plenty of pep, 40-41 mpg, nicely appointed, plenty of room,etc. I'm sure some experimental aircraft manufacturer will come up with something like this that will run on mo gas with ethanol, or straight Mogas. I can remember when this prius type engine was not even thought of. Plus it's very trouble free.
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The thing is, Jim, that my 1985 Escort with a 1.6 L gas engine and a five-speed manual transmission averaged about 35 MPG, my 2001 Saturn with a 1.9 L gas engine and a 5-speed manual transmission averaged around 41 MPG, and my 2012 Kia Soul with a 1.6 L gas engine and a 6-speed manual transmission averages around 36 MPG (or 39 MPG if I use ethanol-free gas), all with a lot less complexity.

Granted, I'm a bit of a hypermiler, and I always beat EPA estimates by a significant margin. Even my 2006 Saturn Vue SUV got close to 30 MPG with some moderate hypermiling techniques. So I'm wondering how much more efficient the hybrid drivetrains really are.

My understanding is that where hybrids really shine is in the stop-and-go kind of traffic where conventional drive trains are inefficient. Even when I lived and worked in the NYC Metro area, I really didn't encounter very much of that. I was able to schedule most of my stops along schedules that avoided most traffic tie-ups. And where I live now, there simply is no heavy traffic. I'd have to drive a couple of hours to find some. So maybe my numbers don't represent a good comparison.

Also, my preference for manual transmission has to be considered. That adds a few MPG if you know how to use it, which not too many people do nowadays. :(

Nonetheless, I've never been all that impressed with the MPG of hybrids because as a group, they don't do much better than what I do with conventional drivetrains.

Rich
 
JHW said:
yeah, they've done a great job of coming up with something very complicated that delivers the same room and only slightly worse mileage than an old VW diesel.
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Uhhh,
not that I want to take Jimmy's side, but try making that VW diesel conform to modern epa and safety regulations. It would weight twice as much and power would be measured in MP (Mouse power; with apologies to the current new engine thread) instead of HP.
 
frfly172 said:
Still have the weight problem of the batteries,also takes to long to recharge ,not much good on long cross countries.
Click to expand...

Vision...

The future of electric vehicles has to lie in standardized battery sizes that slide in/out and "recharge stations" that simply swap 'em out. You have a large vehicle? It might take four packs. A small one might take two.

Eliminates the charging downtime.
 
I agree. It would also eliminate the periodic, and very large cost, to replace depleted batteries. That would be amortized over the life of the battery by the charging stations/suppliers and accounted for by slightly higher battery exchange rates. But that is how companies like "Blue Rhino" do it with propane exchanges.

The downside is that if you exchange a relatively young battery with a soon-to-be-retired battery, you may not see the charge hold up as long. It might make "fuel" planning a little riskier. Each new battery will have it's own profile.

timwinters said:
Vision...

The future of electric vehicles has to lie in standardized battery sizes that slide in/out and "recharge stations" that simply swap 'em out. You have a large vehicle? It might take four packs. A small one might take two.

Eliminates the charging downtime.
Click to expand...
 
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